1.Support Door Weight Up to 500lbs---Tire grade solid rubber material, supper wear-resistant. Hot dipped galvanized finish steel for rust . 2.Universal Use--- gate helper wheel rolls easily over concrete/ grass/ pasture ground. If you plan to use it on soft pea gravel, we suggest you put something in the ground along the wheel path for it to ride more smoothly. 3.Lift your Gate Up to 8-3/4'--- Diameter:6'. There is 8-3/4' from the bottom of the wheel to the center of where the pipe would attach, so the door could be lifted up to 8-3/4'. Width of tire:1-1/2' flat wheel will roll over your driveway's crushed rock surface. 4.Only for Round Fencing Pipe--- Helper gate wheel could be used on both pipe farm gates, chain link gates or any other gate that has a bottom ROUND pipe measuring 1-5/8' through 2'. NOTE: Check your gate frame diameter first.